OBJECTIVE: In the last years, major changes as regards timing for operation, surgical technique, and perioperative care determined a great improvement in the arterial switch operation (ASO) allowing excellent mid-term results in a few leading centers. This stimulated the widespread adoption of ASO as procedure of choice for transposition of the great arteries (TGA), even in small institutions. We reviewed our early experience with ASO in an attempt to evaluate its safety in a small center. METHODS: Since April 1992, 39 consecutive patients underwent TGA repair by ASO in our department. There were 27 patients with simple TGA, 8 with TGA and VSD and 4 with Taussig-Bing heart and aortic coarctation. Median age and weight at operation were 7 days and 3.5 kg, respectively. Neonatal repair was performed in 34 patients. In accordance with the Planché coronary classification, type I was encountered in 21 patients, type II in 4 and type III in 14. Several modifications of the original technique were used, mainly regarding coronary relocation, pulmonary artery reconstruction and approaches for associated VSD closure and aortic arch repair. RESULTS: Early mortality was 2.6% (n = 1), the only operative death being related to unsatisfactory coronary relocation. Since modified ultrafiltration was adopted, mean ICU stay decreased from 5 +/- 4 days (n = 21) to 2 +/- 1 days (n = 17) (P